This application is based on Application No. 2001-359941, filed in Japan on Nov. 26, 2001, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an elevator group control apparatus for efficiently controlling a plurality of elevators of the same bank in an elevator system with two cars operating in one shaft.
2. Description of the Related Art
In cases where a plurality of elevators are provided, group control is usually performed on these elevators. When group control is applied to an elevator system with a plurality of cars operating in one shaft, it is necessary to carry out such group control so as to improve the transportation efficiency of the elevator system as a whole while avoiding collisions of the cars operating in the same shaft, which is the most different from an ordinary elevator system with one car operating in one shaft.
Such an elevator group control apparatus as taking this difference into consideration is disclosed in Japanese Patent No. 3,029,168, corresponding to Unexamined Japanese Patent Publication Hei. 6-305648, for instance. In this prior art reference, there is proposed a control technique in which a car entry preventive range is set for an elevator system performing a circulation type (horizontally movable) operation, so that cars are controlled to be prevented from entering this range.
However, such a prior art technique is based on the circulation-type elevator system as a precondition, and hence it is difficult to apply this technique to an elevator system incapable of horizontal movement for the following reasons. That is, in the circulation-type elevator system, it is presumed that respective elevators in the same shaft run in the same direction, so passing-by of the elevators depends on the horizontal movement thereof, and thus no consideration is given to how to achieve collision prevention and passing-by of cars in elevator systems in which cars can not move in the horizontal direction.
The present invention is intended to obviate the problem as referred to above, and has for its object to provide an elevator group control apparatus which is capable of performing group control on an elevator system having two cars operating in each shaft with improved efficiency while preventing the possibility of collisions of the cars as much as possible. Bearing the above object in mind, the present invention resides in an elevator group control apparatus in an elevator system with two vertically movable elevators operating in each shaft. The elevator group control apparatus includes; a traffic detection part which detects data of car traffic generated in a building; a zone setting part which sets a dedicated zone and a common zone for each of upper and lower cars in accordance with the results of detection of the traffic detection part; an assignment decision part which decides a car to be assigned to a call generated at a hall in accordance with a call generation floor, a direction of the call, and a zone set by the zone setting part; an entry determination part which, when one of two cars in each shaft is coming into the common zone from its dedicated zone, determines, based on the position, the direction of movement, and the state of the other car in the same shaft, whether the one car in each shaft is permitted to enter the common zone; a passing-by instruction part which gives a passing-by instruction to a prescribed floor in the dedicated zone so as to make each car exit from the common zone to its dedicated zone after each car has entered the common zone; and an operation control part which controls operation of each car based on the results from the assignment decision part, the entry determination part and the passing-by instruction part. With this arrangement, it is possible to achieve excellent operation efficiency while preventing collisions of the cars in each shaft as much as possible.
In a preferred form of the present invention, the passing-by instruction part prepares a virtual call at the lowermost floor of the upper car dedicated zone when the upper car has entered the common zone, and a virtual call at the uppermost floor of the lower car dedicated zone when the lower car has entered the common zone.
In another preferred form of the present invention, the passing-by instruction part cancels a passing-by virtual call when a car, which exists in the common zone and already has a passing-by virtual call, is assigned to a hall call generated in the dedicated zone, or when a car call for making a car come to its dedicated zone is given to a car existing in the common zone and already having a passing-by virtual call.